1. Field of the Invention
The present invention relates to a developing cartridge capable of opening or closing a supply port and a recovery port at the same time.
2. Description of the Related Art
Conventionally, the image forming apparatuses of electrophotography such as a full-color copying machine, a printer, a facsimile apparatus and a composite apparatus thereof are based on a so-called tandem system is well known in which a plurality of image forming portions corresponding to each color of yellow, magenta, cyan and black are arranged in parallel, a toner image of each color of yellow, magenta, cyan and black formed by each image forming portion is directly transferred onto the recording sheet, or secondarily transferred via an intermediate transfer belt onto the recording sheet to form a full-color image.
Also, some image forming apparatuses such as the full-color copying machine, printer and so on are based on a so-called four cycle system in which a plurality of developing units corresponding to each color of yellow, magenta, cyan and black are arranged adjacent to a single photoconductive drum along the circumferential direction of a developing device main body, the developing device main body is rotationally driven to move a developing unit of each color to a developing position opposed to the photoconductive drum, a toner image of each color of yellow, magenta, cyan and black is formed on the photoconductive drum by rotating the photoconductive drum a predetermined number of times, and the toner image of each color of yellow, magenta, cyan and black formed on the photoconductive drum is directly transferred onto the recording sheet, or secondarily transferred via the intermediate transfer belt onto the recording sheet.